Contactor with reciprocating armature and novel resilient clip



April 20, 1965 R. L. M GARY CONTACTOR WITH RECIPROCATING ARMATURE AND NOVEL RESILIENT CLIP 2 Sheets-Sheet 1 INVENTOR ZZOZDa'ZLMQ [fa/y,

United States Patent 3,179,771 CONTACTOR WITH RECIPROCATING ARMA- TURE AND NOVEL RESILIENT CLIP Robert L. McGary, West Chicago, 111., assignor to Furnas Electric Company, Batavia, 111., a corporation of Delaware Filed May 1, 1963, Ser. No. 277,370 2 Claims. (Cl. 200-104) The invention relates to improvements in electric switch assemblages and has reference in particular to magnetic contactors for controlling electric motors such as may be employed in air conditioning and refrigerating systems.

.A primary objective of the invention resides in the provision of a magnetic switch of the contactor type which will have positive solenoid action, with easily removable coil and contacts to facilitate inspection for repair or replacement, and which will be more compact with a higher performance rating than other devices of the same type and capacity.

A more specific object is to provide a magnetic switch unit having a clip of spring metal for releasably retaining the molded encapsulated coil of the switch unit in place on the center leg of the magnet field piece and which will not interfere in any manner with the movement of the armature and connected parts when the field piece is magnetized.

Another object is to provide a magnetic switch of the contactor type wherein the arc block and magnet field piece are releasably secured to a metal base member and wherein the plastic encapsulated coil is releasably held on the center leg of the field piece by a spring clamp having releasable securement to the metal base member.

Another object is to provide a magnetic switch of the character described which will incorporate improved mounting means for the several parts including a pivotal connection between the armature and the track members supporting the same for reciprocation movement to and from the magnet field piecewhereby contact of the armature with the field piece is facilitatedin addition to permitting ready removability of the armature for access to the coil.

With these and various other objects in view, the invention may consist of certain novel features of construction and operation, as will be more fully described and particularly pointed out in the specification, drawings and claims appended thereto.

In the drawings which illustrate an embodiment of the device and wherein like reference characters are used to designate like parts FIGURE 1 is a side elevational view of a magnetic switch unit which embodies the improvements of the invention;

FIGURE 2 is a top plan view of the magnetic switch unit shown in FIGURE 1; V

FIGURE 3 is a front elevational view of the switch unit of the invention;

FIGURE 4 is a vertical sectional view taken longitudinally along line 4-4 of FIGURE 3 showing the parts on a larger scale and with the coil energized and the switch contacts closed;

FIGURE 5 is a longitudinal sectional view taken along the line 5-5 of FIGURE 4; and

FIGURE 6 is a perspective view of the spring clip for holding the coil in place.

The electromagnetic switch unit as shown in the drawings has been designed for the individual mounting of the several switch assemblies on a metal base member 10. The said base member has a front leg 11, side legs 12 and 13, and a rear leg 14, all being integral with and bent downwardly from the main body portion of the base member.

3,179,771 Patented Apr. 20, 1965 The front leg 11 is provided with an elongated opening 15 for accommodating the spring clip indicated in its entirety by numeral 16, FIGURE 6, and which provides a resilient retaining member for releasably holding the encapsulated coil 18 in place on the magnet field piece 20. The said legs 12 and 13 each have one or more openings such as 21 and 22 for receiving a screw or the like (not shown) by means of which the metal base member 10 can be fastened to a support. The body portion of the metal base member 10 is provided with the screws 23 and 24 located adjacent the side legs for releasably securing the magnet field piece assembly 20 to the base member in a manner to be presently described. The are block or contact board assembly 25 is also releasably fastened to the metal base member 10 by the resilient pressure foot 26, and by the rear securing screw 27. The rivet 28 or the like, FIGURE 4, fixedly secures one end of the pressure foot 26 to the base member 10, whereas the opposite free end of the foot is adapted to engage the front flange 30 of the arc block. At the rear of the base member the body portion thereof between the rear legs 14 is extended and said extended end receives the screw 27 which passes through the rear flange 31 of the arc block to fasten the said element to the base member.

The field piece 20 which provides a magnetic core for attracting the armature when magnetized by the coil 18, is composed of metal laminations cut into the shape of an E to thus provide the outer legs 33 and 34 and the center leg 35. Cover plates such as 36 are located on respective sides of the laminated field piece and the metal laminations, together with the cover plates, are securely bolted together to form a unit by the rivets such as 37. The legs 33 and 34 of the field piece are additionally held together by the shading coils of copper identified by numeral 39$. The cover plates do not cover the'sides of the center leg 35 which is left free for accommodating track members for carrying the armature at one end and a contact carrier at the other end which elements will be presently described.

The coil 18 consists of many turns of wire and which are eventually encapsulated by any suitable plastic, the complete unit having a general rectangular shape with ,a center rectangular opening of a size to receive the middle leg 35 of the field piece. In this manner the coil 18 is mounted on and is operatively associated with the field piece. The encapsulated coil is provided with a projecting terminal on each side such as 40 and 41, for electrical connection, respectively, with the positive and negative terminals of an energizing circuit.

The magnetic field piece 20 and associated parts are releasably secured to the base member 10 by the screws 23 and 24 previously referred to and which are adapted to coact with the bayonet slots 42 and 43, respectively.

The slots are provided in the laterally extending base flanges of the cover plates, each cover plate 36 having a base flange 44 formed integral therewith and extending for approximately the length of the bottom leg of the field piece. When the screws 23 and 24 are released the field piece 20 can be moved to align the screws with the enlarged openings 42 and 43, and since these openings are larger in diameter than the screws, the field piece can thus be lifted from the base member. The structure provides a convenient and a highly satisfactory fastening means for the field piece with easy assembly and disassembly of the parts.

The cover plates 36 are each cut away to form a channel or groove as shown in FIGURE 1. The said channels receive the track members such as 45 and 46, respectively, located on opposite sides of the field piece and which are thus supported so as to permit reciprocating movement thereof. The track members, formed of non-magnetic material, carry the armature 48 at one end and at their opposite ends the contact carrier 56, FIGURE 4, is fixed thereto. The armature 48 is also formed of metal laminations held together by rivets and the said armature is pivotally secured to the track members by means of the plastic pin 51. The pin is removable so that the armature and coil can be easily removed. The pin also joins the armature to the track members in a manner permitting limited pivotal movement whereby full contact engagement is made possible between the armature and the three legs of the field piece.

The track members 45 and 46 are joined at their inner ends and said end connects with the contact carrier by means of the projection 52 of the carrier which is releasably secured to the track members by the screw The carrier 5t) essentially consists of an insulating cross member which carries the movable contacts 54 and 55 located top and bottom on each of the metal strips 56. The strips are loosely mounted on the head shaped projections 57 and each strip is resiliently backed by a coil spring 58. The carrier is equipped with three such projections 5'7 and thus the present contactor could be employed in connection with three phase circuits, although in the drawings only two sets of movable and stationary contacts are provided for controlling a two phase current supply.

The movable contacts 54 and 55 are adapted to coact with stationary contacts at and 61 retained by the arc block 25 as clearly shown in FIGURES 4 and 5. The said block consists of a base of insulating material 62 having side walls 63 and 64 and a rear wall 65. A pair of partition walls 66 and 67 divide the interior of the block into three compartments, each receiving one of the head shaped projections 57. The two outer compartments accommodate the movable contacts and the terminal strips 70 and 71 for the stationary contacts 6% and 61 are accordingly associated with the same compartments.

The two terminal strips 70 are securely fixed to the rear wall 65' by screws 72 and the terminal screws '73 at the top end are provided for electrically connecting the strips to a pair of terminals on the electric motor or other device to be controlled by the present contactor. The strips 70 continue downwardly to extend under the flange formed by the rear wall 65 and the depending end of the strips have the stationary contacts 66 secured thereto. The terminal strips '71 are located on the rear side of wall 65 with the lowermost end of the same having a stationary contact 61 secured thereto. Each strip is like wise provided with a terminal screw 74 in addition to the auxiliary terminal screw 75. The strips 71 can thus be electrically connected to the two lines of the power supply circuit, and the auxiliary terminal '75 can be tapped for connection with a thermal overload relay or similar device such as may be associated with the contactor.

The assemblies comprising the arc block 25 and the eld piece M), are each releasable from the base member in the manner as described. Also, the armature can be readily released from the track members and when so released and removed access can be had to the encapsulated coil 18 for removing the same from the middle leg of the field piece. For yieldingly and releasably holding the coil in place and in operative association with the magnet field piece, the invention provides the resilient metal clip 16 shown in perspective in FIGURE 6. The clip consists of a tongue 76, a front sloping section '77, a finger engaging portion 78 and a pair of resilient arms 50, all integral with each other and preferably cut from a single piece of spring metal. The front sloping section '77 has the projection 81 punched from the metal thereof and said projection extends downwardly and rearwardly for convenient location in the opening located in leg 11 of the base member. In this manner, the clip is releasably held to the base member. With the tongue 7s located under the field piece as shown in FIGURE 4, it will be clearly understood that the resilient arms 3d will engage the coil and in forcing the same rearwardly, the coil will be effectively retained in place on the field piece. The arms Stl are spaced so as to engage the field piece on respective sides of the armature and thus the coil is resilientiy held in a manner which does not interfere with the movement of the armature or with movement of the track members for transmitting the attraction of the armature to the movable contacts.

The encapsulated coil 18 has a rectangular opening for receiving the middle leg 35 of the field piece. The said opening is sufficiently wide so as tov allow the track members 45 and 46 to pass through without any frictional binding against either the middlle leg or against the inside walls of the coil. As a result, the coil could have lateral movement on the leg member. Any such lateral movement cannot be permitted to take place, since the coil, when energized, might tend to interfere with the magnetic attraction of the armature.

The invention accordingly provides positioning cars 82 for side positioning the encapsulated coil. he ears may be formed from the metal of the cover plates 36 or otherwise provided, and said ears project into the rectangular opening in the coil for holding the coil in the desired laterally centered position.

The invention is not to be limited to or by details of construction of the particular embodiment thereof illustrated by the drawings, as various other forms of the device will, of course, be apparent to those skilled in the art without departing from the spirit of the invention or the scope of the claims.

What is claimed is:

1. In an electromagnetic switch, in combination, an arc block assembly, a magnet field piece assembly, a metal base member providing a supporting element for said assemblies, said are block assembly including a block of insulating material recessed on one side to provide a plurality of individual arc-quenching compartments, a pair of electrically spaced contacts in each compartment, terminal strips fixed to the arc block and electrically connecting with the contacts respectively, means for releasably securing the arc block and the magnet field piece assembly in predetermined positions on the metal base member, said magnet field piece assembly including a laminated metal core in the shape of an E, an annular coil supported on the middle leg of the metal core and having telescoping relation therewith, a movable armature positioned for coaction with the legs of the metal core, a pair of track members supported by the metal core for reciprocation in a direction parallel with the longitudinal axis of the middle leg, said track members extending through and beyond the coil in substantial alignment with and on respective sides of the middle leg, a pivot pin for pivotally connecting the armature and the track members, a carrier fixed to the track members at their end opposite the armature, a plurality of contacts carried by the carrier and movable therewith into the compartments to engage and electrically bridge the contacts therein, and a resilient clip for releasably holding the annular coil in place on the middle leg of the field piece, said clip having a part engaging with the stationary field piece and a second part having engaging relation with the base member.

2. In electromagnetic switch structure, the combination with a metal base member, of a stationary field piece having a top leg, a bottom leg, and a middle leg, all disposed in the same extending direction, means releasably securing the field piece to said metal base member, a movable armature positioned for coaction with the legs of said field piece, an annular coil supported on the middle leg and having telescoping relation therewith, a pair of track members located on respective sides of the middle leg and being supported by the field piece for reciprocating movement, said track members extending through the opening in the annular coil in substantial alignment with and on respective sides of the middle leg, a pivot pin pivotally joining the armature to the track members, and

5 6 a resilient clip for yieldingly and releasably holding the 2,087,895 7/37 Bierenfeld. annular coil in place on the middle leg of the field piece, 2,434,096 1/48 Ayers, et a1 200-104 X said clip having a part located under the stationary field 2,921,166 1/ 60 Few, et a1 200104 piece and having contact with the bottom surface of the 3,035,137 5/62 Fumas, et al 200104 same, and said clip having a second part adapted to en- 5 FOREIGN PATENTS gage and interlock with the base member.

References Cited by the Examiner UNITED STATES PATENTS BERNARD A. GILHEANY, Primary Examiner.

1,862,158 6/32 OKeefie 200--104X 10 ROBERT K. SCHAEFER, Examiner.

891,302 12/43 France. 

2. IN ELECTROMAGNETIC SWITCH STRUCTURE, THE COMBINATION WITH A METAL BASE MEMBER, OF A STATIONARY FIELD PIECE HAVING A TOP LEG, A BOTTOM LEG, AND A MIDDLE LEG, ALL DISPOSED IN THE SAME EXTENDING DIRECTION, MEANS RELEASABLY SECURING THE FIELD PIECE TO SAID METAL BASE MEMBER, A MOVABLE ARMATURE POSITIONED FOR COACTION WITH THE LEGS OF SAID FIELD PIECE, AN ANNULAR COIL SUPPORTED ON THE MIDDLE LEG AND HAVING TELESCOPING RELATION THEREWITH, A PAIR OF TRACK MEMBERS LOCATED ON RESPECTIVE SIDES OF THE MIDDLE LEG AND BEING SUPPORTED BY THE FIELD PIECE FOR RECIPROCATING MOVEMENT, SAID TRACK MEMBERS EXTENDING THROUGH 